Cut-out for incandescent lamps



(No Model.)

W/TNESSES. gr

H. LEMP a; M. J. WIGHTMAN.

GUT-OUT POR-INGANDESGENT LAMPS.

Patented June 5, 1888.

ATTORNEYS.

Nrrnn STATES PATENT Fries.

HERMANN LEMP AND MERLE J. \VIGHTMAN, OF HARTFORD, CONNECTICUT.

our-our FOR lNC ANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 383,891, dated June 5, 1888.

Application filed June 21, 1887. Serial No. 211,995. (No model.)

To aZZ whom it may concern:

Be it known that we, HERMANN LEMP and MERLE J. WIGHTMAN, citizens of the United States, and residents of Hartford, in the county of Hartford and State of Connecticut, have invented a certain new and useful Gut-Outfor Incandescent Lamps, of which the following is a specification.

Our invention relates to the construction of incandescent lamps adapted to be used in series upon arc-light circuits, and involves more particularly devices for cutting out or shortcircuiting such lamps in case of rupture of the filament.

In a prior application for patent filed by us March 2, 1886, Serial No. 193,752, we have de scribed an automatic electric cut-out in which the leading-in conductors are brought near together electrically at a given point, whereby they will be fused together by the heat of the are formed on the rupture of the filament, thus offering a shorter path for the current, and thus short-circuiting the arc and cutting out the lamp from the circuit.

Our present invention is an improvement upon the invention described and claimed in the application referred to, and is designed to render the operation of the cut-outmore speedy and certain.

We have discovered in practice that it takes some considerable time for the are which forms at the very moment when the filament breaks,

the arc that plays across between the broken ends of the conductor will at once fuse the leading-in conductors or their extensions and thus short-circuit the lamp without delay.

In the accompanying drawings, which form part of this specification, Figure 1 illustrates a form of lamp embodying our present invention. Fig. 2 is a cross-section view of the cutout wires.

A and B are the leading-in conductors, arranged on opposite sides of thelamp and in electrical connection with the main circuit. These leading-in conductors are preferably made of fiat platinum sheets, as shown.

a Z) are copper wires electrically connected with the leading-in conductors and supporting the filament C From any. convenient point along the line of the leading-in conductors metallic extensions a 1), preferably copper wires, and electrically connected with said conductors, are carried up into the space between the two legs of the filament, as shown. The extensions are in very close proximity with each other electrically, so that they may be electrically united by fusion under the influence of the are formed between thebroken ends of the conductor. They may be separated, if desired, by a thin sheet of mica, which will readily melt in the heat of the arc and allow the melting wires to fuse together. The wires may be surrounded with cement, as indicated at (l, which holds them securely in position and facilitates the fusion under the heat of the are. This cement may be composed of plaster-of paris mixed with borax and silicate of soda, or it may be made of a metallic salt,such as peroxide of lead. The operation of the lamp will be readily understood from this description.

hen the incandescent filament breaks, a voltaic are is formed between the broken ends of the conductor, which plays across the space betweenthe legs, melting the cement and the mica insulation and fusing the copper wires a b together into a solid joint, thereby short circuiting the are and cutting out the lamp.

It will be understood, of course, that the fusing contacts or conductors may be formed in any desired manner, the sole condition of the invention in this respect being that the opposite sides of the electric circuit of the lamp shall be brought together electrically, as de scribed, in the space between the legs of the filament and adapted to be fused together by the heat of the are. 7

What we claim as our invention is- 1. An incandescent lamp having its entertrically in the space between thelegs of the filament and sufficiently near to be electrically united by fusion under the influence of the are formed between the broken ends of the conductor upon the rupture of the filament, as and for the purpose described.

2. An incandescent lamp having its entering conductors brought into proximity electrically in the space between the legs of the filament and continued in such proximity sub stantially the whole height of the filament, whereby they may be electrically united by fusion under the influence of the are formed between the broken ends ofthe conduct or upon the rupture of the filament, as and for the pur pose set forth.

3. An incandescent lamp having its entering conductors brought into proximity electrically, and normally held in such proximity bya fusible cement, whereby they may be electrically united by fusion under the influence of the are formed between the broken ends of the conductor upon the rupture of the filament, as and for the purpose described.

, 4. An incandescent lamp having its entering conductors brought into proximity electrically, said conductors being embedded in fusible cement at that point and insulated from each other by a thin sheet or layer of in sulated material, whereby the conductors may be electrically united at that point by fusion under the influence of the are formed between the broken ends of the conductor upon the rupture of the filament, as and for the purpose described.

Signed at Hartford, in the county of Hartford and State of Connecticut, this 28th day of February, A. D. 1887.

HERMANN LEMP. MERLE J. YVIGHTMAN.

\Vitnesses:

LoUIs M. SCHMIDT, J. A. DALZELL. 

